Telephone-exchange system.



PATENTED AUG. 14, 1906.

H. 0. EDGE. TELEPHONE EXCHANGE SYSTEM.

APPLICATION TILED NOV. 17, 1902.

HARRY 1, .lllligll,

Application filed November 17, 1902.

Specification of Letters Futcnt.

: L llICr'XGO. lLlilNUlS.

.EXGHA-NGE srsrerr.

To all lUhOi/L it may (0111387116 Be it known that l, lliinii'r i). .lluon', a. citizen of the United States, residing at Chioago, in thccounty of Cook and State of lilino1s, heve invented a certain new and useful Improvement in Telephomi-lfixchnnee Systems, of which the following n in! clear, concise, and exact description, reference being had to the accompanying drawings, for1nin a part of this specification. f

iI-y invention relates to telephone-oxchange systems, and has for its object the provision of an improved signaling apparatus at telephone-excl:unges, whereby ulterncting signal-receiving devices, nn'ignetm bells-con be operated at the substations.

The apparatus of my inventionis particularly dcsi ned for use in connhction with those exchanges Where meclmnically-opcrated'gencmtors are not desirably (3113} yed, the invention enabling Inc to use a buttery whose current is caused to produce nllcrnnting or intermittent current for use in signnh m in practicing my invention I associate with the ringing-key of the cord-circuit (or the switching device that is to afford temporary connection of the signaling source of current with it called line) two conductors lending to contacts adapted to be engaged by the ringing-key, these two conductors including the instrunientnlity whereby the current that is to be passed over the line for signaling purposes 1s set up. A battery is inconvenient source of current, which battery is included in series with the two conductors lending to the ringing-key contacts. There is also includcd in the circuit with each of these conductors a primary and a. secondary coil, the two primary coils together wnstituting an inducing winding and the two secondary coils constituting together on induced winding, the coils of each winding, however, being normally in separated relation. The coils of the windings are preferably included normolly in series relation with ouch other, these coilsnormully not beingiin transformer relation, and as the conductors are normally open at the ringing-key the battery in circuit with the ringingkey not wnstedwhen the ringing-key is out of service.

A particular feature of my invention coueists in forum j the induction-coils and the conductorsincluding the same into inductively-reluted circuits, to which end the pri mary coils are directly connected in series. as

- from decnergizing by l are also the secondary coils, which result is effected when the ringing-key is GDQlt'hGd. The preferred menus for effecting this result consists in a relay that is seriallyincluded n circuit with thctwo conductors, the relay being energized upon the nmnipulution of the ringing-key to operate its armature that serves when attracted to directly connect the coils of the prinuiry together and the coils of the secondary together.

i. have thus provided tclopl'ione system comprising :1 cellod subscribers line extending from o. telephone substation to an en:- chnnge, cord connecting apparatus at the change, it signcling-circuit section normally disconnected from the celled -subscribcrs line and including a source of current iucnpnble in itself of operuting'the colled-subscrib' crs signal-receiver, o. ringing-key for making this circuit-section a. continuation of the called-subscribers line, and means included in said section 1" or causing the source of current therein to produce current capable of operating the called subscriber's signahreceiver.

in the preferred embodiment of the invention there is included in. the signaling-circuit section it relay, the armature of the relay and its front contact forming pert-of such section. When the ringing-key is depressed, the circuit through this relay is closed, the armature thereof vibrating to cause an intermittent current in the signaling-section which intermittent current is transformed because of the operation of the other relay, whose armature serves to transfer the signaling-cirouit, now including the called-subsc'ribers line, into inductively-related sections. The relay that determines the relation" between the transformer-coils is desirubl'y not included in. that inductive section of the circuit that contains the signaling-buttcry, but is'rzitherincluded in that inductive section that contains the subscribers line,

' this relo. renminin ener ized b r reason of.

the rupidly-fluctusting current that passes therethrougli, this relay being prevented reason of the sluggishncss of its armature as the current from the battery is interrupted.

p I will explain my invention more fully by reference to the iccoinponying drawings, in which' Figure 1 illustrates one of the many; types of telephone-exchange systems to which the invention may be applied. Fig. 2 illustrates of denionstrutin the applicability of my-invention of t is many ty es of-telephoneexchange enpsrstus st esc of the substations 96 end 120 whereof I have shown a Wellknoivn type of telephone switch-hook 0,3, receiver'iz, sup orted: thereby and shownin this instance es ceing included; in a. closed local circuit; with secondary c of eninductionco iigwhcsc-priciery iriniiui dis shownmseties with the trensmitter a, sin adapted-for inclusion in series with. c tele ilione-line ff uncut the removal; of thcreceiycr from its There issiso shown at the-substation c: megneto-beil g, desirably at high impederce r sistencc, this bell: being included in e bridge betv ,e, he sidesof the telephonelicc, the seidi but-Eg elso; containing s.- canes thssystsm: illustrstedis a, commonfbfsttery system Thetele lionerlinesf terminate in any suitsbi-e mm of linejecir, as conteinin theline-s prings i. These lincesprings ei'eilicstrctcd "with beckcontects. that ricrnislly cause the common better? italic n1chided in circuitwith the telephone-line, whichzcircnit, however, is not complete untilthe receiver at the corre's end; substation; is removed from its ock. Between the bsciccontects end: the common battery there is ncluded,clinersigm m, pref.- ei ebiy of the self restor' type, there being iiiustretcd thisnsrticu er, histence a Weli+ known typeofhue-signal employing a curtein csrr'rediby the armature-lever. Other. types of liue-signsls however, may be eniployed Without departing from the spirit. of

the inventionend othersystems than. commen-battery s stems. may be used, One of 'inuny typcso cord-circuits at the exchange isillustrcted, that shown employing an enstvering plug 0 end a connectinglug 0, Whose tips-ere united by a ti strai1 0 and whose sleevesare unitedlby s sleeve-strand o Elie-battery indicated at p, Which, accordingto wellrknown telephone practice, Ineybe one and; the same with the battery Z, is bridged across the strands of the eord-circuit, there being included imgedance devices 1), which will not prevent t e passage of battery, but will prevent the shunting of voice-currents.

As'forms of cleerihg-out signals there are illustrated electromagnetic q q, similiir to the signsls'm, and there is illustrated in shunt shout each.- signsl g a. condenser; (1 whose purpose is obvious, these condensers serving L to prevent the impedance in-fthe Winding of the instruments q from impeiring the p gress or the voicecurrents. There is also ing-circuit.

assess illustrated a, Well-known form oi operctors listening-key end, iilSt8fl1'i1 '"Oui'/fii3 The ogereti'on of so much of the telephone-exc sn'ge system as hes been described by ref? I am enabled to use in connection; therewith a source of constant current, as the-.bsttery i,

with the aid of but two conductorsiecding to the rhiging-key herring two coniccts. u, whereby I am enabled. to secure e. mi; importent advantage, residing in. ths-eiiiiity: to apply the invention to any standard tweoi ringing-key mechanism Without the @iic fcsion of. additional parts for. such inechsniem;

The two conductors ietwred it. u. are Ina-11y in e continuous 200;), there being, cluded each side; of the loop thcpriineii coils c end thesecondsry coiis oi:v cut-innerformer, the transformer stting; in} their car-- mei relation merely psrtsoi the-conductors ui in the form of; c'u'peretus illustrated iuziiig.

there is included in series with thcbetterzy t a relay '11, whose armature, with its front contact, normally maintains the continuity of theccnductors u. The circuit containing the conductors u" and the bettery t is obviousiy openwhcn. the ringingdrey is oi service. When this ringing-key is thrown into service, the circuit incinding the battery tie closed by. way of the ringing-key and the celled subsoribers line, whereupon the ture of the magnet o is caused to operate the battery, thereupon producing intermittent current, which is momentarily directly impressed upon the entire circuit, including the celied-subscribers line. When the circuit contsinin the battery tis thusclosed,,the relay w, inc uded serially in one of the conductors 10, preferably between the set. of. coils 14 u is energized, the armature thereof immediately causing the wire w to unite thecoils u into at secondary windingzand the coils it. into a primary Winding. After the-coils are thus united into the windings of; the transformer the magnet w is includedi in. that in,- ductive section of the signaling-circuit that contains the coils u so that its continued en.- ergizstion is directly dependent upon the ringing-key, the battery 6 being shunted therefrom, as this battery is contained inthe local primary inductive section of the signeh The armature of the magnet w is maintained in an ettrscted position, even though the current through the same fluctuates, by the adjustment of its armature,

which is made sluggish with respect to the cal circuit with 'clbsttery y, the circuit illus Lil ' claim as new and desire tromagnet trated being the '(ll-liDOWIlBlithe-211'](l-l)l0ll circuit, whereby the armatures of the eleca re tainstantly maintained in vi-' bration. l have indicated an extra armature z, corresponding to the armature on magnet '12.

'lhe advantage of my invention in connection with the modification illustrated in Fig. 2 will be apparent. Circuit is not closed until the relay 112, that is employed in the embodiment of the invention illustrated in both figures, is energized upon the depression of the ringing-key. A condenser 2 may be employed to overcome the sparks when the circuit containing the battery t is interrupted. The plug 0 and the ringing-key ,9 constitute a double control of the circuit, including the conductors n, the control efl'ected by the ringing-key 8 being effected where the plug 0 is employed, not only as an instrumentality for completing the signaling-circuit through the called subscribcfls bell, but'is also employed to complete the telephonic connectionv between the substations. I do not,there fore, wish to be limited to the ringing-key in connection with the cord-circuit performing the double function of establishing signal connections and telephonic connections, as any switching device having so arable relation with a called-subscribers ine may be used with my invention. The magnet is is desirably only operated when the signaling section is thrown into connection with the called-subscriber's line, to which end there may be supplied to the ma 'net w an extra armature 10 included serial? and normally in open circuit with the battery y. When this magnet w is energized, the armature w is maintained attracted and is only maintained attracted during the connection of the signaling-section with the called line.

Fig. 3 indicates a plug o,-that is purely a ringing-plug, with the tip and sleeve whereof the conductors n have direct connection,

there not being en'iployed in connection with this ringing-plug any ringing-key,so called. It in obvious that changes may be made in the apparatus of my invention without departing from the spirit of the invention. 1 do n t, t 'ercfore, wish to be limited to the PI'GClSL .angement shown; but,

Having thus described my invention, l to secure by Letters Patentl. in a telephone-cxchange system, the combination with a telephone-line extending from a substation to an exchange, and provided at its substation with a signal-receiving appliance, a section of asignalin -circuit' at the exchange including a source 9 current and the coils of a transformer, a switching appliance adapted to' separably coilnect the said sigmiling-section with the said telephoneline, and means included in the si paling-secb tion ror, establishing transformer relation between the coils of said trmisformer upon the connection of said signallug-section with the telepl'ionc-line, substantially as described.

2. In a telephone-exchange system, the combination with a telephone-line extending from a substation to an exchange, and pro vided at its substat-imi with a siginila'eceiving appliance, a section of a signaling-circuit at the exchange, including a source of current and the coils of a transformer, a switching appliance adapted to separably connect the said signaling-section with the said telephoneline, and a rclayincluded in the signaling-section for establishing transformer relation between the coils of said transformer upon the connection the said signaling-section with the telephone-line, substantially as deseri bed.

3. in a telcphone-exchange system, the combination with a telephone-line extending from a substation to an exchange. and provided at its substation with a si nal-receiving appliance, a section of a signaling-circuit at the exchange, including a source of current and the coils of a transformer, a switching appliance adapted to sepz'trably connect the said signaling-section with the said telephoneline, and a relay included between the substation and the secondary of the transformer for establishing transfornnw relation between the coils of said transformer upon the connection of the said signaling-section with the telephone-line, substantially as described.

4. In a telephone-exchange systen'i, the combination with a telephone-line extending from a substation to an exchange, and pro vided at its substation with a signal-receiving appliance, a section of a sigmiling-circuit at the exchange, including a source of direct current and the coils of a transformer, a switching appliance adapted to separably connect the said signaling-section with the said telephone-line, and means for establishing transformer relation between the coils of said transformer upon the connection of the said signaling-section with the telephoneline, and means for alternately modifying the circuit containing the said source of current, substantially as described.

5. In a telephone exchange system, the combination with a telephone-line extending from a substation to an exchange, and provided at its substation with asignahreceiving appliance, a section of a signaling-circuit at the exchange including a source of direct cur rent, the coils of a transformer, a switching appliance adapted to separably connect the said signaling-section with the said telephone line, and arelay for establishing transformer relation between the coils of the said transformer upon the connection of the said signaling-section with the telephone-line, and means for alternately modifying the circuit containing the said source of current, substantially as described.

6. In a telephone-exchange system, the

phone-line, a relay included in the signalingsection for establishing transformer relation between the coils .of said transformer'upon the connection of the said signalin -section with the tele hone-line, and means for alternately modiiying the circuit containing the said source ofcurrent, substantially as described.

7. in a telephone exchange system, the combination with a telephone-hue extending from. a substation to an exchange, and pro- .vided at its substation with a signal-receiving appliance, a section of a signaling-circuit at the exchange, including a source of direct current, the coils of a transformer, a switching appliance adapted to separably connect the said signaling-section with the said telephone-line, a'relay included between the substation and the secondary of the transformer for establishin transformer relation between the coils of sai transformer upon the connection of the said signaling-section with the telephone-line, and means for alternately modifying the circuit containingthe said source of current, substantially as described.

8. In a tele hone-exchange system, the combination with a telephone-line extending from a substation to an exchange, and provided at its substation with asi rial-receiving appliance, a section of a signa ing-circuit at t e exchan e, including a source of direct current and the coils of a-transformer, a switching appliance adapted t6 separably connect the said signaling-section with the said telephone-line, means for establishing transformer relation between the coils of said transformer upon the connection of the said signaling-section with the telephone-line, and

means for interrupting the circuit containing the said source of current, the said circuit-interrupter being in the form of an electromagnet having an armature and contact in series relation with each other and the source of the direct current, substantially as described.

9. In a telephone-exchange system, the combination-with a telephone-line extending from a substation to an exchange, and pro- Vided at its substation with a signal-receiving a pliance, a section of a signaling-circuit at e exchange including a source of direct current and the coils of a transformer, a switching appliance adapted to separably connect the said signaling-section with the said telephone-line, and a relay for establishing transormer relation between the coils of said transformer-upon the connection of the said signaling-section with the telephone-line, and

ceases means for interrupting the circuit containing the said'source of current, the said eircuitdn terrupter being in the form of an electromagnet having an armature and contact in series relation with each other and the source of direct current, substantially as described.

it), in a telephonaexchange system, the I combination with teiephone-line extending from asubstaticn a an exchange, and provided at its subs n with a signal-receiving appliance, a s

opposite sides a n s a 1 at current 111 s si nercoil, a'source of d 1ng-sect1on, a sw;

ehing ap liance for sepa n of a signaling-circuit at the exchange, including upon each cf its rably connecting this signa'ing-section with the telephon e-iin'e and a relay included signaling-secticn, connections control i thereby servin to establish transformer relation between t said transformer-coils when the relay is energized, and subdividing the said section into inductively-related primary and secondary portions, the source of direct current being located in the primary portion,

and means for alternately modifying the cincuit containing the said battery, substantially as described.

11. In a telephone-exchange system, the combination with a telephone-line extending from a substation to an exchange, and pro vided at its substation with a signal-receiving appiiance, a section of a signaling-circuit at the exchange normally serially including transformer-windings, a switching a pliance for separably connecting this signa 1ng-section with the telephone-line, and means for establishing a transformer relation between said windings-when said section is connected with the telephone-line, substantially as described.

12. in a telephone-exchange system, the

combination with a telephone-line extending from a substation to an exchange and provided at its substation with a signal-receiving appliance, a section of a signaling-circuit at the exchange normally serially including transfor1ner-win.dings, a switching a pliance for separablyconnecting this si na ing-section with the telephone-line, an means for establishing a transformer relation between said windings when said section is connected with the telephone-line, a source of direct current 111 the signaling-section, and means for alternately modifying the circuit containing said source of current, substantially as described.

13. In a telephone-exchange system, the combination with a telephone-line extending from a substation to an exchange and provided at its substation-with a signal-receiving appliance, a section of a signaling-circuit at the exchange, normall including trans former-windings, a switc ing appliance for se arably connecting this signaling-section with the telephone-line, and means for cstablishing a transformer relation between said windings when said section is connected with the telephone-line, substantially as described.

14. In a telephone-exchange system, the combination with a telephone-line extending from asubstation to an exchange, and provided at its substation'with a signal-receiving appliance, a section of a signaling-circuit at the exchange, a switching appliance for separably connecting this signaling-section with the telephone-linq and means for establishing a transformer relation between said windings when said section is connected with the telepl1one-line, a source of direct current 15 in the signaling-section and means for alternately modifying the circuit containing said source of current, substantially as described.

In witness whereof I hereunto subscribe my name this 10th day of November, A. D 20 1902.

HARRY O. HUGH.

Witnesses i GEORGE L. ORAGG, A. D. RUssELL. 

